Fresh aerial parts of the S. trilobata were collected from CSIR-Central Institute of Medicinal and Aromatic Plants, Research Centre Pantnagar (Uttarakhand) in summer (vegetative stage), rainy (vegetative stage), autumn (flowering stage) and winter (flowering stage) seasons. The experimental site is located between coordinates 29.02° N, 79.31° E and an altitude of 243 m in foothills of northern India.

Volatile oil yield varied from 0.18 to 0.25% in different seasons, with the maximum in winter season. Altogether, 43 constituents, representing 96.1-97.3% of the total oil composition were identified. Major constituents of the oils were alpha-pinene (78.6-83.3%), alpha-phellandrene (1.3-4.1%), sabinene (1.4-1.9%), limonene (1.2-1.9%), beta-pinene (1.0-1.6%), camphene (0.7-2.0%), 10-nor-calamenen-10-one (<0.05-1.5%), germacrene D (0.1-1.4%) and gamma-amorphene (<0.05-1.3%). The comparative results showed no big differences in the oil composition of this plant due to season of collection.